StarDestroyer.Net BBS

So, I understand TDIC is a "heated" topic in these parts.

projectile weapons are seen as primitive and no one uses them any more (other than the TR118 rifle that the crazy vulcan modified with a transporter device to murder through walls).

The thing is though, whilst E = MC^2 is more or less the very basic formula for a nuclear bomb - and those do make big booms, things like those, or antimatter weapons require, as you say, a warhead. An expensive warhead in terms of maintenance, in terms of generating X amount of antimatter (or uranium etc). You need staff to look after them, they have a shelf life etc.

But what about just getting a photon torpedo casing, filling it with iron, and throwing it at something?

Do you know what is a lot like E = MC^2?

E = 0.5mv^2

Well it might not look much the same but they are.

V is for Velocity. If you make that velocity very close to C (speed of light), then it looks an awful lot like nuclear bombs.
Impulse is meant to be 0.25 C normally. Let's take that figure. That's 0.25C. That's our velocity.

Now let's add the mass. Iron (for the sake of argument) has a density of about 8 grams per cubic centimetre. (7.87).

Photon torpedo casing that doesn't need a warhead, warp sustainer, guidance system etc (i.e. it's a projectile) they're about the size of a coffin. Give or take? Say 2.5m by 0.8m by 0.5m ? Heh that's exactly 1m3 of iron. That's 8 tons of iron.

E = (0.5 x 8000) x (0.25C)^2

E = 4000 x 5,617,219,867,105,110

E = 22,468,879,468,420,440,000 joules.

https://www.wolframalpha.com/input/?i=2 ... 000+joules

= 5.37 x 10^9 tons of TNT

= 53,700,000,000 Tons of TNT

= 53 gigatons per torpedo.

That's an order of magnitude higher than all the nuclear weapons we've ever tested. Per lump of iron launched at full impulse at a (stationary) target.

Fakeedit: I may or may not be an order of magnitude out here, but either way the point stands

Some links:
https://www.youtube.com/watch?v=V__P3N7sPW0
https://www.youtube.com/watch?v=FcS09dBSrvc


So, ignore the hypersonic shockwaves but 0.5 second fireballs, how much *kinetic energy* was being thrown at the planet?

Assume Romulan Green Glowy Things are the same as Federation Red / Yellow Glowy Things - same with Cardassians and their Yellow Glowy Things - in space, they all seem within an order of magnitude of themselves so no real differences there in calcs at the end of the day.

The dialog goes directly against what we see visually, and usually visuals are treated as a higher level of canon on this forums.

However, that being said its entirely possible that the energy weapons were causing a good chunk of the planet's crust to vaporize* which is why we don't see the massive explosions and ejecta material one would have expected based on the dialog.

*the main site goes into some detail as to why the "vaporize" is a very poor word to describe that happens when something gets disintegrated by things like phasers in Star Trek; namely, there would now be a giant hot cloud of gas that would immediately kill everything near it. According to the TNG manual the matter is "pushed out of the continuum," what ever that means. Another possibility is that the matter is being converted into neutrinos.

http://www.stardestroyer.net/Empire/Tec ... Beam1.html

Well, how do you accelerate your lump of iron to 25% of lightspeed? It the propulsion comes from the torpodo you'd have less mass for your warhead. Does it come from the ship firing? Since ST-ships use some mass-lightning technology - IIRC - to achive higher sublightspeeds, do we know, if they are even capable of accelerating a torpedo to 25% lightspeed with their onboard energy-systems? And what about guidance-systems? For a weapon where you only need to shoot straight ST has phasers and disruptors.

FTeik wrote:Well, how do you accelerate your lump of iron to 25% of lightspeed?

Um... fire it whilst you're at full impulse. Just aim your ship so you have a collision course roughly and fire away. Torpedo tubes seem to have a slight off axis firing ability so that can make up for any exactness.

And what about guidance-systems?

You don't need them - you're firing at a planet or large stationary target such as Space Dock.

This would be useless in ship to ship combat of course.

IIRC, according to the TNG tech manual part of the impulse engines act similarly to warp engines, just to a lesser degree (This could also explain why the Romulan warbird was capable of FTL speeds despite only having impulse power in "Balance of Terror"). Going to full impulse doesn't necessarily mean that the ship is actually accelerating to 0.25c via conventional physics as a subspace field is involved as well. An object fired from a starship might not have the same kinetic energy as something that is accelerated to 0.25c via regular physics.

They pretty much can't be using a conventional KE-reaction drive for sublight speed, because the engines are setup directionally, and yet they have no problem stopping without turning around! Also this might be argued would also explain why they use 'bank to turn' instead of making flat turns ect...it could be some trait of these special kinds of drives that makes that appealing. With conventional drive systems in space a flat turn would require less thrust.

If the sublight drive is warp based too then simply turning off the power would logically revert the ships velocity to whatever it was before the warp effect began. Or at least that follows a logic, and the ships true velocity in the universe would return to whatever it was before the ship used impulse/warp since nothing is ever stationary in any realistic sense in the universe.

Sea Skimmer wrote:They pretty much can't be using a conventional KE-reaction drive for sublight speed, because the engines are setup directionally, and yet they have no problem stopping without turning around! Also this might be argued would also explain why they use 'bank to turn' instead of making flat turns ect...it could be some trait of these special kinds of drives that makes that appealing. With conventional drive systems in space a flat turn would require less thrust.

If the sublight drive is warp based too then simply turning off the power would logically revert the ships velocity to whatever it was before the warp effect began. Or at least that follows a logic, and the ships true velocity in the universe would return to whatever it was before the ship used impulse/warp since nothing is ever stationary in any realistic sense in the universe.

That might actually explain a lot. IIRC we've seen ships appear to "slow down" and "stop moving" when the impulse drives have been turned off or disabled.

The idea of engines that give you marvelous speed by neutralizing or reducing your inertia, and then abruptly stop having any effect when you switch back the power so that your previous momentum vector reasserts itself...

That's an old and time-honored one; Doc Smith used it in the 1930s in the Lensman series, for instance. It had some interesting side effects when applied consistently.

It would also explain why ships that lose impulse power are so often in danger of falling into planets or whatever. They're not in stable orbits, they have some random momentum vector that 'belongs' to another star system entirely. If impulse power is suddenly switched off, and if the ship's reaction thrusters can't provide enough delta-V to cancel out, say, 30 km/s of velocity the wrong way, you could end up smacking into the planet in pretty short order.

Of course, in that case, you would pretty much have to do extended reaction thruster burns, or tractor-assisted maneuvers or something, before you could ever dock with anything and switch the engines off...

Simon_Jester wrote:It would also explain why ships that lose impulse power are so often in danger of falling into planets or whatever. They're not in stable orbits, they have some random momentum vector that 'belongs' to another star system entirely.

On the gripping hand, I always thought it meant the ship was in a "powered orbit" (which isn't really an orbit) — thrusting down (or up) with the impulse engine so that the ship's total motion vector didn't necessarily match the orbital velocity it "should" have for the height of its orbit. Can't remember now where I came across the concept; might have been one of the Pocket novels, or a Blish novelisation.

So, when the impulse drive goes >phut< due to Klingons on the starboard bow (well, scrape them off!) or Scotty forgot to feed the dilithium crystals, the ship's orbit instantly changes to unpowered... which might or might not involve imminent lithobraking.

That sort of begs the question, though, why would they spend all their time in powered orbits if they have easy maneuver capability? It's not that hard to park yourself in a stable orbit, so unless you specifically need to hover at one place above the planetary surface at low altitude for a special reason or the like...

[shrug]

Simon_Jester wrote:so unless you specifically need to hover at one place above the planetary surface at low altitude for a special reason or the like...

<nod> That's the most common reason I've seen in discussions of this. It can go two ways; a "hover" at lower than geosynchronous orbit gives you loiter time over a site of interest, and a "fast" orbit lets you cover the whole planet for e.g. close-range sensor sweeps in less than half a day (that's how long it would take with a natural atmosphere-grazing orbit).

(For people who aren't into orbital mechanics, the "hover" orbit is the one that gives you a dramatic plunging-to-your-imminent-doom climax for the advert break; the other one tosses the ship in a waytheheckoutthattaway direction.)

Simon_Jester wrote:That sort of begs the question, though, why would they spend all their time in powered orbits if they have easy maneuver capability? It's not that hard to park yourself in a stable orbit, so unless you specifically need to hover at one place above the planetary surface at low altitude for a special reason or the like...

[shrug]

Could be in case they need to beam up/down - having a planet in the way (if you're orbiting on the far side) probably means you can't beam people up on the far side of the planet - so they hover above where their away team is. Normally you'd go "ok, geo sync it then" but if the away team isn't at the equator perhaps Picard or Kirk prefer to literally "hover" above them.

But then "Standard Orbit", which is said nearly every time.

I hope Spacedock is in a proper orbit. You don't want that falling down, do you?

Hmmmmmm *Re-reads tech manual"

The impulse engines use a subspace field in addition to generating thrust conventionally, though the subspace field is usually only needed when the ship is travelling at higher speeds.

I re-ran my calcs, it's 10x less - in the 5GT range (per iron lump @ 0.25C).

Can I ask a physics question here: At 0.25C there'll be some relativistic effect that is noticeable.

Assuming a launch from a torp tube at full impulse (0.25C) and then the ship just buggering off, that object, that iron lump, that'll just continue at 0.25C, right?

Canon wise (show only) ?

If that's the case, does "relativity" have *any* effect on the KE of its impact?

The only thing I can think is that going at that speed, does mass not increase as speed goes up?

So would it in fact be some sort of factor toward more destruction, as it's going so fast (on top of E = 0.5m * v^2) ? Say (arbitrary number) 25% more mass due to going at that speed, would that make 8 tons now effectively 10 tons (8 + 25%?) ?

I know it won't be 25% btw, I figure it's an exponential curve thingy.

Prometheus Unbound wrote:I know it won't be 25% btw, I figure it's an exponential curve thingy.

Very much exponential — if you look at the curve of relativistic effects as velocity goes up, you don't get much of significance happening until you get well over 1/2c. At 1/4c the effects might not even be all that noticeable without instruments.

SpottedKitty wrote:

Prometheus Unbound wrote:I know it won't be 25% btw, I figure it's an exponential curve thingy.

Very much exponential — if you look at the curve of relativistic effects as velocity goes up, you don't get much of significance happening until you get well over 1/2c. At 1/4c the effects might not even be all that noticeable without instruments.

That's fine, I don't need it to to be. Just someone on another forum is taking issue with my KE calcs saying that Relativity would mean they have no mass since they're going so fast and I'm thinking "that doesn't sound right" - but then I'm not a theoretical physicist.

Sounds like they've got their fractions the wrong way round — as velocity approaches c, the mass increase approaches infinity.